Backside-illuminated InAsSb/GaSb broadband detectors

This letter reports the achievement of a high-performance, broad-spectral-band infrared detector with the InAs1−xSbx alloy system using a backside-illuminated heterostructure approach. The basic structure of the detector is obtained with InAs1−xSbx grown by a liquid phase epitaxy technique on a GaSb substrate under lattice-matched or nearly lattice-matched conditions. The measured photoresponse covers the spectral range 1.7–4.2 μm with an external quantum efficiency of 65% without antireflective coating. The typical zero-bias resistance area product is in excess of 109 Ω cm2. The typical leakage current desity is less than 10−9 A/cm2 for 100 mV reverse bias. All parameters were measured at 77 K.